As a reaction to the increasing noise pollution, caused by the expansion of airports close to residential areas, porous trailing edges are investigated to reduce the aeroacoustic noise produced by flow around the airframe. Besides mechanical and acoustical investigations of porous materials, the fouling behavior of promising materials is an important aspect to estimate the performance in long-term use. For this study, two sintered fiber felts were selected for a long-term fouling experiment where the development of the flow resistivity and accumulation of dirt was observed. Based on 3D structural characterizations obtained from X-ray tomography of the initial materials, acoustic models (Biot and Johnson-Champoux-Allard) in the frame of the transfer matrix method were applied to the sintered fiber felts. Flow resistivity measurements and the measurements of the absorption coefficient in an impedance tube are the basis for a fouling model for sintered fiber felts. The contribution will conclude with recommendations concerning the modeling of pollution processes of porous materials.
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http://dx.doi.org/10.3390/ma9080709 | DOI Listing |
Adv Sci (Weinh)
January 2025
State Key Laboratory for Modification of Chemical Fibers and Polymer Materials & College of Materials Science and Engineering, Donghua University, Shanghai, 201620, China.
High-performance bulk graphite (HPBG) that simultaneously integrates superior electrical conductivity and excellent strength is in high demand, yet it remains critical and challenging. Herein a novel approach is introduced utilizing MOF-derived nanoporous metal/carbon composites as precursors to circumvent this traditional trade-off. The resulting bulk graphite, composed of densely packed multilayered graphene sheets functionalized with diverse cobalt forms (nanoparticles, single atoms, and clusters), exhibits unprecedented electrical conductivity in all directions (in-plane: 7311 S cm⁻¹, out-of-plane: 5541 S cm⁻¹) and excellent mechanical strength (flexural: 101.
View Article and Find Full Text PDFBraz Dent J
December 2024
Post-Graduate Program in Oral Sciences (Prosthodontics Unit), Faculty of Dentistry, Federal University of Santa Maria (UFSM), Santa Maria, Rio Grande do Sul, Brazil.
The aim of this study is to assess the presence of MDP at various stages of the bonding procedure, enhance the adhesive and mechanical behavior of cemented zirconia ceramics. Fifty ceramic slices (15 × 15 × 2 mm) and 48 discs (Ø= 10 mm, 1 mm thickness) were prepared, sintered, air-abraded with aluminum oxide, and allocated considering: 1) microshear bond strength (µSBS) between ceramic slices and luting agent cylinders (height= 1 mm, Ø= 1.2 mm); 2) fatigue behavior, ceramic discs paired and bonded onto fiber-epoxy resin discs (Ø= 10 mm, 2.
View Article and Find Full Text PDFACS Appl Mater Interfaces
January 2025
Institute of Atomic and Molecular Physics, Sichuan University, Chengdu 610065, China.
As a high-performance cermet, TiCN possesses extensive potential for application in various fields, including coating materials, ceramic products, and electronic materials. Here, the effects of temperature and pressure on the physical properties of the TiCN cermet have been investigated by high-pressure techniques and first-principles calculations. Experimentally, the phase, microstructure, mechanical properties, and electrical conductivity of bulk TiCN ceramics were analyzed.
View Article and Find Full Text PDFMaterials (Basel)
December 2024
Department of Metal Forming, Welding and Metrology, Faculty of Mechanical Engineering, Wroclaw University of Science and Technology, 50-370 Wrocław, Poland.
This article presents research on advanced surface preparation methods for sintered carbides (WC-Co, grade B2) commonly used in the tool industry, particularly in the context of bonding these materials with C45 steel using adhesives. Sintered carbides are widely used due to their high hardness, wear resistance, and good ductility, making them ideal for manufacturing tools operating in harsh conditions. Traditional bonding methods, such as brazing and welding, often result in stresses and cracks.
View Article and Find Full Text PDFJ Colloid Interface Sci
February 2025
State Key Laboratory of Solidification Processing, Shannxi Province Key Laboratory of Fiber Reinforced Light Composite Materials, Carbon/Carbon Composites Research Center, Northwestern Polytechnical University, Xi'an 710072, China. Electronic address:
Multifaceted balance makes the design of ceramics difficult but is urgently needed. This work purposes to grow uniform edge-rich graphene (ERG) on alumina (AlO/ERG) in-situ, then constructs a discontinuous conductive, strengthening and toughening network of crosslinked ERG by mixing AlO/ERG with AlO and sintering. Under the guarantee of the tight-bound covalent interface, ERG and doping AlO strengthen and toughen the ceramic by synergistic effect of weak and strong interface.
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